Downton Abbey Stars Tease the 'Epic' New Movie and a Possible Sequel About the 'Next Generation'

The beloved TV show Downton Abbey wrapped its final sixth season in 2015, but the cast never lost touch.

“There was a WhatsApp group,” Hugh Bonneville tells PEOPLE.

“Isn’t there one called ‘DA Bitches’?” Allen Leech asks.

“That’s with me, Lily James and Laura Carmichael,” Michelle Dockery says of her on-screen cousin and sister, respectively. “Just the girls. But there are a few now.”

Once everyone returned to Downton Abbey to shoot the anticipated movie, “It was this great reunion,” Dockery, 37, says.

Rumblings of the series heading to the big screen began even before Downton Abbey ended, but the official announcement didn’t come until July 2018.

“There was never any doubt that we wanted to, but it was a question of could we actually make it work,” Bonneville, 55, says. “It was a sense of relief when we did actually get there because the logistics of getting all of us back together was really what was the most challenging. Coming back and putting on the familiar clothes and being back in that familiar setting was fun.”

Bonneville jokes it took “about eight seconds” to fall back into character as Crawley patriarch Earl of Grantham.

“Playing a character this long, it’s like muscle memory,” Leech, who plays Tom Branson, adds.

Since the show’s launch in 2010, fans on both sides of the pond have fallen in love with the characters — and so have famous musicians.

“Laura Carmichael and I were in a party in New York and Mick Jagger came over to us and very casually was like ‘Ello, I’m Mick,’” Dockery recalls. “And we’re like, ‘We know!’ And he then said he’s a huge fan of the show.”

Bonneville connected with The Rolling Stones’ Ronnie Wood on Twitter. “He was toasting the show with a cup of tea,” Bonneville says. “They [the band] used to rush through rehearsals in order to get back in time for the show and then if one failed to watch a show, they would have to say, ‘No spoilers’ as they tuned up for ‘Satisfaction.’”

Bringing the Emmy Award-winning series to the silver screen put some pressure on its stars.

“We all felt the obligation to make it big and bold enough for the cinema. That was the biggest difference,” Leech, 38, says. “We all came with the attitude and wanting this to be an epic experience and a more lavish, luxurious experience for the fans.”

The film sees Downton Abbey getting a royal visit from King George V and Queen Mary. But the stress of the preparations and the main event have Lady Mary Talbot (Dockery) questioning whether it’s worth keeping the Abbey open any longer.

“It certainly leaves some ties left undone,” Dockery says. “I think there are a few of those in the film. There’s this feeling of the next phase, the next generation. So who knows?”

If the Crawleys do stay in the Abbey, though, Bonneville, Dockery and Leech agree they’d be down to continue revisiting the franchise in some way. “We would!” Dockery assures.

Adds Bonneville, “It’s sort of a complete downer because there’s not another one next week. There is an appetite and an affection for it that hopefully we can satisfy in the future.”

Downton Abbey is in theaters now.